- MCLr579/V

~~TRflflSLHITIOfl ( d -.) O fCHEMISTRY OF ORGANIC SULFUR COMPOUNDS IN CRUDES AND

•1 PETROLEUM PR iDUCTS

, By Various Authors

~ October 1960

~~ 51 pages

Zvw

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-Go aw MCL..- 5/V

0

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addressed to:

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-t

AKMADE24YA RAUKf S3j.

Bashkirskly Filial

WWII~rYA G.RGAZICRF.AIj SOYM2I'IY,

SODE2R1AZUC)WULYA V NEEM'AKII I u'nQPRDUKTrAiK

IZDATE.'11'VO AKAD~~aI N"W SSSR

Moskva' 1959

Vwteu *6-27, 276-283, 284.-292, 304~-315

6 439/

9ACA.DEXY OF SCIENCES USSR

Bashkirian Branch

CNERISTRY OF ORGANIC SULFUR CCU(POUNDS fIN CRUDES

AND PEIWLEUI PRODUCTS

.9'.m o tms cdy f3lncsUS

X'ev 95

tN1 P57/

Tableu of Contents

The Corrosive Properties or 3ulfur-Bearing Crudes, by L. D. Zakharochkinand S. M. Vol'fson. ...................... . .

The Corrosive Properties of Pucla' Produced from 'u1•Ir-Bearing Crudes,by 1. Ye. 3.eopolov, 0. V. Pletr.eva, et al . * . .0. * ... . .. .&

Organic Slf'ar Compoun1. in FPels as Corrosion 1nhibitors for Copperand Its Alloys, by Ym. B. Chertkov, V. N. Zrelov antl V. M. Shchagin . . .

The Effect of Organic O1iilfr Compounds on the Loa-Temperature Propertiesand Oxidlzability of Kerosene-Gasoll Fractions, by I. A. Rubinshteyn,B. V. losikov, Ye. P. Sobolev, ani M. C. Zaychik . .. . . .. ....

THE CORROSIVE PROPERTIES OF SULFMR-BEAK.ING CRUDES

by

L.D.Zakharochkin and 3.M.Vo01fson

(Giproneftemash)

Academician I.M.Gubkin, who for a long time headed all geological research con-

nected with the prospecting, exploration, and development of oil and gas fields,

vhen speaking or the problem of the expansion of crude oil production in the foot-

hills of the Caucasus and in Central Asia, always emphasized the Importance and

timeliness of the problem of discovering now petroleum and gas-bearing deposits In

the flatlands of the USSR.

The decision of the Party to establish the great oil base of the Second Baku in

the region between the Volga end the Urals Initiated an extensive developmentýof the'

subsurface resources of the immense plains of the USSR. The expansion of the pros-

peating, exploration, and development of oll and gas fields In the Ural-Volga

petroliferous region has led to the great growth of oil extraction in these regions.

iMst of the crudes 'of the Ural-Volga petroliferous region are sulfur-bearing.

The total sulfur content in the crudes of the Eastern oil fields of the USSR varies

S or a very vide range, from 0.3 to 4.5 wt.%. The sulfur in these crudes Is mainly

in the fora of organlo sulfur compounds, mercaptans, sulfides, disulfides, poly-

sulfides, thiophenes and other.compounds (Bibl.1). These types of sulfur compounds

Include nmerous groups of sulfur compounds, whose differences are due to the alkyl

groupe bound to the sulfur. But we also find orudes that contain •ydrogen sulfide

o I

and elementary sulfur together with orgunic sulfur compounds.

In refining, the sulfur compounds in crudes and petroleum products undergo

various transformations, as a result or which we have to do in practice, not only

with natural sulfur compounds eantained in the crudes but also with the products o

these transformtti one.

X.G.Rudenko and V.N.Gromova (Bibl.2), while investigating the thermal stabili

cf several sulfur compounds, have shoan that the mercaptans are the most stable of

those sulfur compounds. The substitution of the hydrogen in the SH group by a rad

cal, i.e., the conversion of mercaptans to sulfides, increased the thermal stabilil-

of these compounds manyfold. 3ulfides are distinguished by high thermal stability

regardless of boiling point and class. It Wa also found that high thermal sta-

bility is characteristic of all sulfur compounds with sul'lr in the ring.

Work on the catalytic transformations of sulfur compounds (Bibl.3-5) has shot.

that catalysts act strongly both to lower the temperature at which the transforma-

tions of sulfur compounds begins and to increase the degree and depth of these

transformations. The sulfur compounds here undergo various reactions (liberation

hydrogen sulfide, hydrogenation, dehydrogenation, disproportionation of hydrogen).

The direction of the reaction depends on the nature of the sulfur compounds, the

type of catalyst, the temperature, eta. MiAtuai transformation of the sulfur com-

pounds takes place during catalytic reactions, but ultimately all these processes

proceed irreversibly toward the formation of hydrocarbons and liberation of sulft-

In the form of hydrogen sulfide.

Some sulfur compounds contained in crudes (elementary sulfur, hydrogen sulfi- -

wercaptans) and the transformation products formed during refining by organic suV-.

ocmmowide are sources of intense corrosion of refinery equipment.

Wany years of USSR experience In refining sulfur-bearing crudes from various

"* .ll fields of the Soviet Union have shown these crudes to be of varying corrosive

activity. The ability to evaluate the corrosive properties of sulfur-bearing cru'-ý

and their knowledge is important for practice, since the equipment of refineries

and the cost of protecting it from corrosion is of course riled by the aggressive-

ness of the crude3 being refined. Until recently, there was no method in the USSR

for evaluating the corrosive properties of sulfur-bearing crudes. During the first

stages of larg4-scale refining of sulfur-bearing crudes, their aggressive properties

were attributed to the total sulfur content, but it became obvioud later that the

total sulfur content in crudes from various oil fields could not serve as a cri-

terion of their corrosive properties.

In this c-nnoetion, an accelerated laboratory method of estimating the corro-

sive properties of crudes was developed at the State Institute for Petroelum

Refinery Equipment. The method makes it possible to determine the direct indices of

the corrosive activity of crudes distilled at temperatures up to 3500 C under at-

muspheric pressure, and to determine the quantity of hydrogen sulfide liberated

under these conditions. A detailed description of this method was presented in a

paper before the Second Scientific Session devoted to the chemistry of organic

sulfur compounds.

The principal results of work on the corrosive properties of sulfur-bearing

@eadea of a number of @1 flields In the Kuybyshev and Orenburg Oblasts, and of

Tartary and Bashkiria, are given In the Table. The experimental data have shown

° that a considirableogroup of specimens of sulfurm-bearing crudes examined, contain-

Ing 0.28 to 1.99% of sulfur exhibit low corrosive activity when subjected to at-

oapherie distillation up to 3500C, and approach the low-sul•Our crude of the Baku

region (Smarakhan) in their corrosive properties. The quantity of hydrogen sulfide

liberated on their distillation did not exceed 250 - 260 mg per liter of •rude, and

t*e'rate of corrosion of carbon steel due to these crudes did not exceed 0.5 mm/year.

Vith Increasing amount of hydrogen sulfide liberated on distillation an in-

creased oorrosive activity of the crudes is also noted. In cases where the amount

of hydrogen sulfide liberated was 400 - 600 ag/ltr of crude, the rate of corrosion

ICL.579/V 3,i

of carbon steel rose to 0.8 - 1.0 mr/nyear, and at 60X - 100•0 rg/ltr crude it reached

1.7 - 2.3 mm/year.

The crudes examined also incluied sulfur-bearing specloers with very high cor-

rosive activity, which yielded 1630 to 9500 me of H2 S per liter of crude on distil-

lation, and showed a rate of carbon steel corrosion amount.ng to 2.5 - 6.8 nub/year.

The experimental data show that an extensive group of crudes from the Ural-

Volga petroliferous region, which are usually grouped :ocether under the commuon

designation of 0sulfur-bearing criies" do in fact include crudes with sharply dif-

faring corrosive properties. As the petroleum industry developed in the regions be-

tween the Volga and the Urals, the variety of the crudes has increased year by year.

Corrosive Properties of Sulfur-Bearing Crudes

S0

t . .bk •

Petroli ferous -t 0 ao aCrude Horizon !4t. o

LO -.d4

(b' . ~s o.S

ftakhany Devonian, seaim II 38 V-S 0,84073 0.77 44 0.16o . Shkapov Devonian, seam IV 15 Vii--56 .15453 0.59 56 0,t5

S°° ittriyev °° Devonian 2I V-SC03601 t.28 O.0 70 0.22. . .

HIkhaylov Carboniferous suite, , JV030I3 6 - 12

•°~~~. &ki to ... • Ma V •,o•'.600 a2 a

54 o-t�S- 0.8-1-32 0.76 I.4 a 0.28

khalov Carboqerous suit, 0 003

(Baku -z 0V- 90 I 0A9 49O 0.38

* ?ekrovek Cazbcnif•erous suite- 8nlterts uit V-,5~ .5 1 48 I t 1 • 156 0.41

sea m IIl V--.5 0.85451t5.54 1,.7 178 0.32Z•higuevuk Devonians V-111 0.84765V 8.47 1.52 t19 O.3•eraflmiv Devonian, seam 1 3 V1-56 0.8392 8.36 1.03 160 0.18Seramow Devonian, seam IV 17 VI-56 0.350 5.83 M0.5 215 0.29

* SeitrinoY Devonian, sam II I -5 0.8263 9.5t 0.86 178 0.56Rowmshkin' Devonian - 0.8V60 0 29,59 1.52 I9 0.49

oCs I s 2 .

~CPokrovkCabnfrusitsut 9 V5 .50.45 .5 16 04

(Table Continued)

0 Al i .) 1. O

4- 0

PetroliferOUs 3 I o i. o -. ii k I I u 6. I-4 0 . •

I, rA P-.*1 .-Crderio !- I., •2 I •'• ,,

o I I . •o - oca

A 1 01.4• 0

a Z S.. no

Shkapov Devonian, seam IIbikhany Carboniferous, suite, lo :' O.CM - 40-3 .8

sea IVIPokrovsk Batcrai~aeVi ~ 7 ~~ .I l.i S

ForVi Bashkirian stage

ul tancul1" Devonian 1 . 78 5.9 rx97ol Iny Carboniferous suite, !,,I I.1101

se m 181 V -56 ,O.l~ lh Orpi IA . 39 6• .1Zol 'nyy Carbonifrerous 3U ~ V-.In8~7 tO63 1 I'

Strel'na Carboniferous suite 1.66

Tarkhany Carboniferous Uite S..; Yablonyy° Kunrurian st.aCe, o q ' "i .... < "" ! ° * ° " °sOal I I 2

0 . 1& 1 5 .1 1.7,. S T 5 3 .1 2

BDytugsenf Carboni rerous suito - 1.Radayevsk Carboni terous sulto, i, " ' It NJI.m 8.; 3.07P IW1101 :.l.0

Ssrnovodsk ~Carboniferous suiteq, 50-.~ow~ii.(XI 3. I's A7 Chorizon B-2• t

1A-2 -5 O.W01t 70.7.8 2.50 '1v, 5.

Starokazan Artinian stage i 6.8318~IIshimbay Artinlen stage°

East Stepa:novsk lallno suite " V-55 0.872 17.2A 2.94

Kalino Seam•or upper 10a 31.. o3i.WNW 36.25Permian deposits o

fSpecimen of crude obtained at Petroleum Institute, Academa of Sciences USSR.

eeSpecimens of crude .obtained at A11-ZnIon Petroleum Industry Research Institute.

Besides the highly aggressive crudes of Ishlmbay, Sysran, linel', Stavropol'

and Bugwuslan, which were the principal crudes refined between 1936 and 1944, new

I4

"" C C CCs PC1

l'CL ,,-: 79/V ° o 0 °• ° .. °:. . + . •.. ° + . .. o + ° + •

oil fields have been disiovered and put Into prflduftion during the last 13-12 yea

yielding crudes differine sharply in their total sulfur content and in their corr

sive properties. Further than that, not only new oil and gas-bearine areas -ere

developed, but also new produ-tive strata. For instance, such a new stratum whic

yielded crude soon after the war and opened up a new stage in the develop.ent of

oil production in the regiors between the Volga and the Ural were the Devonian do

posits. Devonian oil was discovered in Western Pashkiria on the Samara Luke, res,

Saratov, in Tartary, and In other areas of the Ural-Volga region. The sulfur con.

tent in the crudes from the Devonian horisons does not exceed 1.5 - 1.6%, and in

number of cases it is as low as 0.8 - 1.04. The Devonian crudes contain sulf.ur a,

pounds of higher thermal stability, and are unaggressive when distilled up to 3534

Considerable quantities of crudes being produced today are from the Carbonif"

oce deposits, with low sulfur and only slight corrosive activity. Such :arbonifel

ous crudes Include those from Mykhany, Mikhaylov, and Pokrovsk.

The figure shows data cIt.racterizing the pattern of growth of the production

both highly aegressive and weakly aggressive erud,:.s In the Ursl-Volga region. Tim

highly agereasivo crudes include those from Staro-Ishimbay, Vvedenovsk, Starokazaw

Tman~y Carboniferous suite, Ahugurs, the erodes produced by the Kirnelneft' Trusi

(Zoulwy. . treiny, Tablony Gorge, Carboniferous suite), the crudes of the old ares

of the 4"ran region, the crudes produced by the Pervomaysk-Chernovsk Trust, thecrudes from the Radayevsk Consolidated ¢Oilo elds, and the crudes produced by the'

Oaguruslanneft' Cob' ne.

The low-corroilon crudes include those from Bashkiria, Tatary, and Kaybyshev

Oblsts, some crudes from Carboniferous deposits, with relatively low sulfur, exhit

Ing only slight corrosive properties, and the crudes from Saratov and Stalingrad

The data in the figure show that in 1940 the crudes produced in the Ural-Vol&

region consisted mostly of higb-sulfur and highly aggressive crudes (92.2t). lates

B I

• o o o/

beginning in 1/. - 11)45, the contribution of the highly aggressive crudes to the

total oil production in these regions fell sharply, in 1945 it was 76.6ý, in 1950

20.1%, in 1955 M).0. Allowing for the prospective development of the individual

Contribu io ofLwAg "siv n Hg-ggO5Y

CotIt~ olaw-a-gresie;sv 2 n - igh-se gressive

a) lows! b) Plan

a='ll•mmring regions, It In calculated that In 1%60 the contribution of• the highly

The chemls that have taken place in the pattern of the properties of the

ý06des produced In the Umrl-Volga regiJon (wo iato the corrosive, aggressive proper-

U"l of" the crudes) advance the problem of organizing the rational and separate col-

loction, •storage, transportaotion, and refining of a wvide range of sulfur-bearing °•'

a-ndos,. We arw very clear at-out the fact that these questions, not be solved not •• •

Or with respect to the corroive, propertieos of the crudes, but also with respect o

t the other physical and ahemical propertiLes of the crudes, the directions of the

_-ftoll pronesav the geography of all-field and refinery location, allowing for the

eWdsting peans of transportatca, eta. :

NX--7--

In spite of the difficulties In the -ay of oreanizing a rational and separi

collection and refining of the eastern erudes, we must still recognize the ipeor-.-

tive necessity ofe suih separatlon, and the work undertaken in this direation by

petroleum indiustry must toe dec!.ively continued and expanded.

The propisitions about the organization of rational collection and refinir4

the crudes of the 'Jral-Volga region should in our opinion be worked out by the

Councils of National Econonmy of Tartary, Bashkiria and Kurybyshev Oblast with th,

participation of a number of re3earch institutes of the petroleum industry, and

should be reviewed arid approved by the higher-echelon directive organizations.

At the same time, we also consider it possible and expedient, even today,

note certain priority measures which result from an analysis of the existing

situation.

1. Up to now oil fields have appeared where it has become necessary to est.

11sh conditions for the separate collection of crudes. Such oil fields include

those of Tuymazy, Mukhan and Shkapov.

2. Since it has become the practice to concentrate the refining of the moo

aggressive sulfur-bearing crudes at three refineries - Kuybyshev, Sysran and

Ishinbey - it is expedient to concentrate all the refining of crudes of this ty..

othesereflnories,° and to permit no deliveries of aggressive crudes to any other

kimeries whatsoever, to say nothing of refineries not equipped to handle sulfur

boarinc crudes. (Gurlyev, Orsk, Grosnyyp, etc.).

3. It is imperative to work out measures and put them into effect graduall,

woer a abort period (lo 1.5 year) to adapt the equipment and the Individual l_

""ts of the general plant installations at the Kuybyshev, Ishimbay, and Syzsran

oflniers to handle highly aggressive sulfur-bearing crudes, in order to effect

amadm reduction in the extent of corrosion and the amount of repair and riebul

* •we at these refineries.

h,.,

Con-ilusions

1. The results of this work have shown that an extensive group of crudes of' the

Ural-Volga region, usually lumped together under the common designation of sulfur-

bearing crudes*, in fact include etudes differing sharply in corrosive properties

when distilled under atmospheri . pressure up to 3500C.

2. The changes that have taken place in the pattern of the properties of crudes

produced in the Ural-Volga region (with respect to their corrosive properties) In-

sistently demand a decisive continuation and expansion of' the efforts taken by the

industry to organize the separate collection and refining of a wide assortment of

crudes of the Ural-Volga region.

3. It is necessary to introduce into the practice of the analysis of the crudes

from now oil fields and horizons a determination of their aggressive properties by

the developed method in order, on the one hand, to determine the rational points for

refining such crudes and, on the other hand, in building refineries, to provide the

most correct and economically advisable measures to protect the equipment from cor-

rosion, according to the degree of' aggressiveness of the particular crudes involved.

4. The work on development of a method or estimating the aggressiveness of

sulfur-bearing crudes and petroleum products under the conditions of high-temperature

processes (tera and catalytic cracking) should be aciatinued.

Ja0ior Scientists S.T.Moshcheryakov and .V.Tokareva, and' Laboratory Assistants

* O..Kalinina end G.G.Zhukova, participated in the experimental pert of this work.

1. R•ihs$S.N. - ulfur Compounds in Crudes. Ind.lbtrol, Vol-39, No.352 (1953)

2. RodenkoM.G. and Cromova,V.X. - Thermal Stability of Certain ulfur Compounds.

Dok.-AN 885, Vol.81, No.2 (1951), p.207

C. o Cd

3. Tits-3tvortsaO,1.N., Llavna,S.ya., Leoqnov&,A.l., and Kazasowa,X@.A. - Zhur.Qre

KhM.., Vol.21 (1951)t p.2422

4. ?ts--Uv~rts~va,l.?., Lovlna,S.Ya., L~cnov&,A.I., end Karasev&,Y*.A. -Uch.Zap.

Iihsk.Goo.Univ., No.132, Vol.? (1950), p.254

S. Tit&eSkv@rts~iBI.N., Locnova,A.X., and Sewin&,S.Ye. -Dok. AN SSSR, V01.81".

Ne.4 (1952), p.741

I.,4

WCLC4 C C1

* MTH 00RIROIE PROPERITIES OF FUELS PRtODUCED FROM

\ SFlUR-DEARING cRUDF.

S. by

!.Ye.Despolov, O.T.Pletnevat Ye.V.Kolotushkinas

- Ge?.De27ayeva, and K.SJal~yshava

* ~(*21-Union kesesich Institute for Petrols= and Gas Refinuing

and for the Production of Synthetic Uqdpd Fuels)

With the widespread introduction of fuel TS-19 produced fram sulfur-bearing

crodes and therefore containing up to 0.25% sulfur, the various consumers became

concerned about Its possible corrosiv" action on fuel-feed Vat=@s.

from the literature di~ta, referring primarily to fuels for carburetor angines,

wo know of the corrosive action of active sulfur compounds, including hydrogen

Jo

mftideo elementary sulfur, and mercaptans,, on various angifie parts (ibl~l).

According to the production technology of ?S-l aind T-2 fuels that has bean

~aptd at thie various ýplants, them-e fuels awe now completely ftae of hydrogen, Sul-

ride.

I

As for' their content of elmesntar7 oulfuz, this elamsnt has beau ~detected In,

eam eeral conercial batch*& of TS'- In amounts ýnot exceeding 0.001 - .0The

.total mereaptanu sulfur I:L fuels T3-1 and T-2. produced from sulfur-bearing crudes,

.see vWr within a wide range (0.005 - 0.30).

: Th.rsec or moeraptains In T3-1 ftel has mad. It necessary to study the

OeurOeve Action or these fuels on the various parts of the fuel systam In turbojet

2i~c.?I .1

_ _-*i

-- V -~ ~ ~ ~ T- - .- O ZV - P_ RTI_ S OF _ _ _ __ _ _ _ _ __U_____S_________U________________

o- ngines, and to establish standards for the permissible content of mercaptan sulfuz

in such fuels.

The corrosive properties of the fuels were determined from the weight loss of

•a msal strip after immersion of 100 hrs in the fuel, at 600C. Earlier joint studii

by the Research Institute for Petroleum Industry and the VIAM had established that

Table 1

Corrosiveness of Turbojet Fuels Produced from Sulfur-BearingCrudes, as a Function of their Content of Kercaptan Sulfur

(Tests on Copper and Bronze 7B-24)

Original Fuel Copper Bronze VB-214Sulfur Content, % Weight_

Fu]L Total .ercaptan a) a)s oLSotr- ~SuLfr Sulfur 4

"T.1 0.12 Absent Absent Absent Absent Absent*.4 0.0m 0.6 t t.4

* 01.7 0.010 -. - . 3.3

A . 0.16 0,M5 O.124 0.3 0.014 9.300,30 0.050 O.a o... 00..

T-2 O.t4 0.nn Absent, 0.8 Absenst I .

0,.:.n •" Sfl 0tEll 2.5 3 3,5S 0.15 0,01.) O.(E1S 3. 7.6

6- 0.17 0o.445 6.00 - 6.2 0.04. 12.3..14 0,23 0.0m0 0.038 9.3 0.024 14.2

a)i oercaptalf• r Content of Fuel after Test, wt.%

;': fuel T-1 with a mercaptan sulfur content up to 0.05%•, had no corrosive action on

.4 "eeverol metale materials used for parts of the fuel systameof turbojet engines:

bronze Br AZ11-1O-1,--4 aluminm alloys, and- steel. A detailed study of the corro-

"' siveneoe of vaious samploes of fuels T3-. and T-2 produced frm sulfur-bearing

o,' erude ws conducted with materials most sensitive to the corrosive action of

* 5 nmoroaptans: bronse VD-21 and copper.

:4t. -TM Inveetipatn was mde ean somploes of fuo T3-1 and T-2 contaidnig 0.002

7-3 .0.0% of sleaptan eulAr. Cersial and expeiamental samples of the fuels were

c ,1/v2

. gelatinous jieposits on the springs and a sharp decreae In the mercaptan sulfur

eontent of the fuel. The chromate passivation of the cadmizsd springs exerted a

* protective action but did not completely prevent the formation of the gelatinous

esposit oan the springs when tested in this fuel.

ouel T3-1. containing 0.01 aercaptan sulfur, causes no formation of gelatinous

Table 4

""aight Loss of Cadmised Springs (ga/mg ) during the Test

ObToaptu Test Conditions for Cadmised SpringsSulfur f' passivated | asivatd

Fuel Content In Fuel In "us in FuelIn Fuelos1f ml- a) Over a iShaken/ a) Over a IShakernI lgater with W Iater I with

.... Cushionj Water Cushion Water

41311"49)--

T+;t I.I OS I • I* a+" °" 23 I+ 1 + °+ * 1",15.1 a 6s AV% tT$.1 0.026l 6.44 160 1677 9.63 1.1. 71.6Tj -1 00. j

III 0I0 j".00 40.00 0.70 13.&1 9126"" ""T-2 O.O 1 L.O l6,01 3s.52 0.9 0.38 1.20

a) In umoistened fuel

' deposits iA tiest on eadmized springsr In untoitered tfuel9; and, very smafll amounts of'

depoelts In tests in fuel watered by shaking with water.

owegt fpassivateu abia 'etdi tfid& ftlU iaSh.

tr.ae3 slIghts and the sontent of nercaptan sulfur in the fuel rmains practicallywe.e

0°:.1 ** °0 •

.0 ( + 4' Thus,. indew rather severe test conditions, when cAdeised springs are tested . 0

i.... + + -l *el o+•op un g 0.0• aercapn sulfur, ehvate possivation of the springss,

. r•iab3 protects the ce•dum coating and prevents the fotiation of gelatinous

deposits even wha the fuel is strongly moistened (ftel with suspended water). Under a

.. o the teot mtditioma, the corrosiveness of ftel T-2# with 0.02% mercaptan sulfur, is

slanla to, that of fuel T3-1 with the sae mer•aptan sulfur content. In tests with

~~ 00 .~~13000 . .~

0 . ° . o..

It will. be seen fr Table 2 that, under the test conditions adopted, copper

Is considerably corroded by the fraction boiling in the range 60 - 230 0C and very

little corroded by the 130 - 20°C fraction.

Thus the increased corros'vaness of ftel T-2 for copper may be explained by t -

* •Table 2

Corrosiveness of Fractions with Boiling Ranges of 60 - 230 and130 - 2AOoC, of Straight-Run Products of Sulfur-BearingCrudea, as a Function of their Content of Mercaptans

Boiling Range Mercaptans In Coer-

Sof Fra.tion, Original Cnt of Weight lss

ocftel., wt,. Fuel after of Strip,Tes •t wt.% g/

0.0M1 Absent 0.500 -OOCm 2.810

00-130 0.015S 7;.1)G.M5OAS10.60)

"0.065 0o.0

"0,001 Absent 0,400.0m5 0,003 0.40

130-240 O,Ot1 0,012 I ..0.0m 0.017 1.800.%54 lot detemined 3.tI

eonalderably higher corrosivity of the low-molecular mercaptans contained in fuel

T-2 - coemprison with the nerc1tans cIn fiuel TS-l.- .

As alrea4 mentioned, fuel TS-l, manufactured in the plant Installations# M

time containes slight amounts of elmentazy sulfur.

o+ i iaul eperiments made with tlest smplesl to which various amounts of eo-

ma intw7.slfkr. had been added, showed that the presenee of elenentaz, sulfur up to

Sl O.02% In the Auls i.*., in amounts that could'not be detected by the copper-stri

teet (00ft 6321-52)9 do not Increase the corrosive action of fuel TS-1 with 0.018%

aeresptanb an brofse VD-Z. With respect to copper, the corrosive action of fuel

"' TS--1 cntalnig meraptane is sharply intensiflid on addition of elaewntay sulfur

"; teothefe.e On addition of O.0*M of elenmtar umlfur to thefooel, the weight

+•. c . .... 57 + o 1, o+1

¼(%

-loss of the copper strip after 100 hr of test increased from 0.5 to 9 p, L.e., by a

factor of 18. Here there was a considerable decrease in the mercaptan sulfur of the

.fuel.

It Is of great practical importance to elucidate the character of the corrosion

of metals in sulfur-bearing fuels, as a function of the contact time. With this

object, we ran experiments on the corrosion of copper and bronze VB-24 in fuel TS-1

and T-2 with varying amounts of mercaptans at varying test durations. Figure 3 gives

the ro'.Z.ts of the tests.

I* will be seen from the data in Table 3 that, 'IL the test temperature of 60OC,

bironw V13-2 begins to undergo corrosion in fuels TS-l and T-2 almost from the in-

stuit of Immersion In the fuel, The mercaptan content decrease is simultaneous with

the weight loss of the strip in the fuel* The corrosion of a strip of bronze VB-2.

under test conditions in fuels TS-1 and T-2 with up to 0.015% mercaptans ended after

• 3M0 bra, while in the fuels containing frm 0.025 - 0.050% mercaptans, it ended

after 150 hrs; during this period, the mercaptans contained in the fuels were con-

pletely used up.

Under similar test. conditions, the interaction of the morcaptans In fuel T-2

(and especlally In fuel T13-1) with the copper'strip is con'siderably slower. ¼ ¼¼¼

ToThe reslts ot the experiments show that the corrosion of bronze V8-24 does not314¼

-so mach depend i 'the amount of .:.orcaptans in the fuel'as *on the contact tiae be- ¼ C-°

tween the bronze and the fuel. During the first 25 hrs of the tests, the corrosion

4of bris.e V-21 lw. slight, and was practically the same- for all fuels with %ercap- . ooo

tam ,contenti of 0.0. -0.05%. ¼'Thls ma eplain the observation that under: operat-

--¼jg eanditimnsi when fuel Is continually being ppedwtrugh the fuel prps, the °

edoaIoeian of the bronse parts is slight and is practically the same for T3-1 fuels

with 0.002 and 0s026% mercatAws.

Te eadmised parts of the fuel stin proved sore sensitive to the ation of

•mreatu slfar. Under engine operating conditions, in regions with elevated at-]I

¼ "• , " o ° , :: " o ° ". . 1 .. =. . ¼" ¼, o . . .¼. ... . .

nospheric himidity, the formation of gelatinous deposits on the cadmized surface of

Spump parts was noted, which in some cases interfered with operation of the fuel

6,

To elucidate the causes and conditions of formation of these deposits in op-

erating with fuels produced from sulfur-bearing crudes, the appropriate laboratory

• tests were run an industrial samples of fuel TS-1 containing 0.01 and 0.025% mercap

Am sulfur and fuel T-2 containing 0.0.% aercaptan sulfur. For comparison we also

ran tests on fuels free of nercaptan sulfur: fuels T-1 and fuels TS-i from sulfur-

-•bearing crudes that had first been treated with sodium plumbite. The series-

-produced steel springs, cadmised both unpassivated and after chromate passivation

-were also tested for corrosion by these fuels.

The test of the cadmized springs for corrosion was run at room temperature for

5 50 dsas, changing the fuel every 10 days, with complete imersion of the springs in

the fuel. To elucidate the effect of Increased moisture content of the fuel on the

* rate of formation of the gelatinous deposits on the cad•ised parts, corrosion tests

San the springs were run at various moisture contents of the TS-i and T-2 fuels.

1)i flwotereJ fue;, I -1ý

- 2) Fuel watered by storage over a water cushion;

- 3) Fuel watered b. shaking- with distilled water, followed by storage o

over a water cushion.

The corrosive action was estimated from the weight loss of the springs, frvm

Mti che In their appearance, and ftom the change in the mereaptan content of ther

-ftel Particular attention was paid to the time of first appearance of the gelati-

-- uns .deposits an the springs, and to the mount of such deposits. Table 4 gives

-data on the weight loss of the springs.

* 5As wi•L be seen, from these data, the greatest weight loss was noted for the

u'aplasvatd springs, tested in the fuel containing 0.02% mercaptan sulfur and

-watered by shaking with water. In this case, we noted the formation of extensive

UJ- 16

C: Cý A

'40 7014 e_____ _atm

4 c

4a4

JO - - - -0

iJiritt cd a c c z

6 1'~IW TOM __ _ _ _ _ _ __ _ _ _ _ _

S %2

I.C V4 I.-c

IMICil d Sd smd,.u C

o ~ ~ ~ 2 on~l CCU-

17. I e n 4

gelatinous deposits on the springs and a sharp decrease in the aercaptan sulfur

eontent of the fuel. The chromate paseivation of the cadised springs exerted a

" protective action but did not empletely prevent the formation of the gelatinous

deposit an the springs when tested in this fuel*

Pool T5-1@ containing 0.001 mercaptan sulfur, causes no formation of gelatinou

Table 4

eIbght Loss of Cadmised Springs (gm/n 2 ) during the Test

lbroapta Test Conditions for Cadmized SpringsSulfur Un•Issivated NPassivated

!1.1 ContentPol of Oigi IFulIFuln nFs

mel a) Over a Shaken a) Over a Shaker.Water with Water withOuhio Water Cushion Water

TS1 olt 0.0Ma on 4.0 tI 3.4 &e .1 u0TS.1t a 41%t

. T3.1 O.Me• 8.44 10o6.0 106.77 sea 13.7 71.53"T-3 0.0 1 t." 4.01 35.2 0.9 0,38 t.20

"a) in umoistened frul

depomLts •in tests on cafeised sprngs In unatered fuel, and very afl amounts of

"",dposits in tests In -ftol atwod byshmkingvwithwater.

TM. lsee of we•dht of passivated cadefied springs tested in this fuel is eo-U°sl °.ghti and the oontent° of orpaptan afufr •nc the fuel rnanis practicafoo

* .°'. hso. wnmix rather severe test conditions# wbeq A Admsed sp-ings are tested

o ,,inT$-l. ,e r contining 0.0t•, Oreaptan, sulf", chrimate passivation of the spring.

l. • ah. pretfts the eadotl costing and prel nt, the, formation Of gelatinous

* depoits evw when the fuel Is strengl moistened (fuel with mspended wate). Undei

th test emnditionse the corrosiveness of ftl T-2& with 0.02 nor' , Is

,,. si r to. that of ftel T3-1 with the m er"ptan sulfu content. In tests with

) .N.... .. . .

C C C .CC

Co". . . o • .. . . C o oo o O ,o o • o •o • o • Co o • • O oO QC o

-sping Ina fel reeof mercaptan sulfur, no formation of gelatinous deposit& was

oborW

Obviously the weight loss of the springs and the formation of gelatinous de-

posits takis place as a result of the interaction of cadmium with the nercaptsns of

-the fuel (directly or by way of intermediate products) forming cadmiumi wrecaptides.

-The weight loes Is In good agrement with the data an the decrease In the smeaptan

&uftr content of the test fuel.,

The gelatIncms, precipitate rwoed from the cadmised springs consists of 715%

- fuel and 219,5% cadmium imercaptides. The following percentage data were found an

* dterinaionof the selmotary composition of the cadmium iseroaptides Isolated froin

the precipitate:

Wri~yrogen 000 0.. 0 8.5

Cadmiiu * e e e e * e 26.5

100.0* It wil be easily qeem -that the relation between the sulfu content and the

cod oontent of the separated inercaptides is close to theoretical. To dam.-.4tatethepresence of cidmin ieroaptides In the gelatinous precipitate formeds the

la&tter was treated with 50% sulfuric acid, and the free wreraptane we"e separated.

In erder to etuaty In weri detail the Influence of water on the formatimon f the

.guaatiamas deposits on the caftised parts of fuel pinps operating on misrcaptam-

j-sesatalinng fuels,, a~ddtional experiments were run. 3peclimens of mnetallic eadalna

wee taken fbr the test In the tozu of cylinders 10M -In length and 6-7 In

* dimmeter. 3ms of the cadmxo specimens were machined before the testg, to roe

Abe eadi exide this their surfaces. The sa&A~ui specimens weetested In T3S-.

'uel with 0*04% neroaptanm alftar under the following conditions: In fuel first dried

wvith eaUlm tqdride, ioe., practicall free even of dissolved, water: In fuel first

- shaken with water wad stored over a water layer.

The eadoium specimens were tested for three months at room temperature in glA

flasks without access of air. In the moistened. fuel, the formation of a large

aount of gelatinous deposits on both cadmium specimens was observed as early as I

-following day.

In the dehydrated fuel, the character and rate of formation of the gelatinow"

deposits was entirely different. On cafetim specimens from whose surface the cad-

mium oxide had been removed, the gelatinous deposits appeared in the form of iso-

*lated points only on the tenth day of the test. During the next two months,, the

asit of these deposits Increased slowly, and only toward the end of the third

month did it Increase sharply. On the cadmium specimens coated with cadhim oxide

traces of deposits appeared only 2.5 months after the beginning of the tests.

* Prallel with the tests of specimens of metallic cadmium we ran the foflowis

experiments under similar conditions: To the fuel TS-l, first dehydrated with

* ~ ealelm hydride, small amiuts of synthetically prepared hydrated cadmium oxide w4

added. The hydrated cadmiumn oxide for the experiments was either air-dried or

:14 i=lt. In the experiments with the moist hydrated cadmium oxide, the formation ol

- slaV1tInoss deposits was observed on its surface on the day following the beginntni

= efr the ý otest -The qautity-of these -deposit. rapoidly increased.' In ther iperimen

-with the air-dried hydrated cadeim oxide, no gelatinous deposits could be detecte

w It* suarface daring the entire test. When these, experiments were run., thole ar

tUn slfur In the fuel smiples was determined before and after the test. Table 5

jtrWillbeseem fcm these data that, In thedehydratedfupl, the hydrated

-emead~txde react considerably- faster with the Sercaptansof the, ftel than

metaL@ic eadolium does. The presernce of water In fuel containing mercaptans accel,

_ates the reaction between the mercaptans of the fuel and the metallic cadmiump as

wveUla the rate of formation of the gelatinous deposits.

5'4I~cl~572D

I

The formation of the gelatinous deposits on cadmium coatings, on contact with

f!uels containing mercaptans, may perhaps pass throu.h the intermediate stage oft

formation of hydrated cad-im oxide.

, Table 5

Measurement of Hercaptan Content In Fuels during the Test

. (Mercaptan Sulfr in Original Fuel, 04,0)

Keraptan Sulfur in Fuelafter Test, %

SpeciLme of Cadmium ZnFuel I In Ful Mo1ies-

Dried with toned bycalcium Shaking with_ __ Hydride Water

Cadmium without oxide film 0.016 0.002Cadmium with oxide film 00026 0.002Air-dried hydrated 001

cadmiumn oxde000Moist hydated cadmium oxide 0.002

1. The corrosion of copper and bronse VB-21 by fuels prepared frcm sulfur-

-bearing crudes is due primarily to the presence of mercaptans in the fuel. Fuels

free from mercaptans shov practically no corrosive action on copper and bronse

2. The presence of up to 0.002% f elmentary sulfur in theinrcaptafl

:-centanning fuel TS-1 does not Intensify the corrosive action of this fuel on bronse

VS-,% but increases it sharply with respect to copper.

t . 3- flel T-29 which is a wide cut containing mors meraptans than fuel TS-l, has

a eswrosive action on copper. The fact that ftel T-2 has a greater tedmiency to

esadocapper is explained by the conesiderabli greater corrosiveness of the low-I,.

.. 'mle•ular maercaptans contained in the 60 - 130eC fraction of ftel T-2.

o. The basie eause responsible for the formation of gelatinmao deposits on

j-.d. isedpa•, t mmrsed in fuel T3-1 snad T-2 frm sulfur-bearing crudes Is the

VI

I+ t-ýwaterlng of the fuels In the presence of mercaptan sulfur.

" " 5 . With increasing content of mercaptrn sulfur in the fuel (over 0.01%) the.

anomnt of gelatinous deposits on cadnized parts sharplv LIcreases.

6. The chrmote passivation of cadmised parts increases their resistance to theSi

oerrosive action of mercaptans and completely prevents the formation of gelatinous

Ideposits on cadmised parts in fuels TS-1 and T-2 with a aercaptan sulfur content not

ove 0.010.

On the basis of this work it has been established that of anl the metallcLlei :

materials used in manufacturing parts for fuel pimps, cadmium coatings are most sub-

Jeet to the action of nercaptanso In this connection, the mercaptan sulfur in20.

fel TS-l and T-2 should not eaxeed 0.0o%.

DIDLIOGRAPMI'

2. Nometkin3.S$. - Petroleum ChiLstr7. AN SWRO1 Moscow (1955), p.29

210

32

4 t

4 4".4 'I 44..

44 0. C .. 44-3 .

4444 4 4,4 4 4 04 + -+ 40+ 4"+ +-

14. ' 44 [

4444+ 44 .o ,., *0

S* o

.. . + '°+ + .

°- I I

4' o444 4 4 '

4

OiRANIC SULFUR CCKPOUWDS IN FUELS AS CORROSION INHIBITORS FOR

COPUt AND ITS ALLOYS

Ta.3.Chertkov, V.N.Zrelov, V.M.Shchagln

(Research Institute for Fuels and lubricants)

The corrosive action of fuels designed for use In gas-turbine engines io an

* Important index of their quality. In the presence of sulfur cmapunds there is &

.eonsiderable weight loss of copper or its al1oys, of which numerous parts of the

,vul system of such engines aie mad. (Mi.-l - 7).

A moe careful study of the question revealed that not all sulfur cmpounds

present in ftels have a.tendency to corrode metals (Bibl.8). It mas established

-that elementaz7 sulfur and the miercaptans belong to the ~me-diina corrosive

epmuus (3Ibl.9*% B.)o.tt the earlier geez lan for all mercaptas &lso

Sprov Inaccurate. The aercaptans of aliphatic structure do have strong corrosive

propeties with respect to copper &Ad its give~. As for mercaptans, of aromatic

-struture# they were faund to exhibit no corrosive activity at temperatures up to

.12OC. Tbeousivie actkv•ty of a sAfel dec'reses to sero a" the thiol group in the

* erati meoapanspreentapproaches a rin4 structure. Frenpe hoahhi

-Sidith1or1eoa1e3mol* whe present in' large 4014Oaitb Sn fels, gjfl not, corrode

-brose, whereas nonalmereaptan Is a powerftl corrosive agent with respect to this

Tables 2 and I give a characterisatimn of the corroeive action of el•matazyS23

m cl', . .. . .. ... o°° o

Table 1

CorroJve Action of White Spirit Ina the Presence of 111mnutary S~alfiar

Concentration of 119e- Co.. ouln, IDeposits an I arface of Bronse,sultary Sulftw. % vD ranse, pjw2 JMagnification So x

Without elmuitaz01lftr o'

0.110. 3.5 3

V.0

Table 2

CorrSITe ActITitY Of White Spirit In the Presence of Merceptans

NOrcptafs I or- Deposit1OO* an rface of Bronze,

Name and con- simsIL Brons., xaUliicgtion So xcmntration T @qiU32

WithoutJlreraptang 0

( ~o.CH4) 2,.

(og(rs.5)S 2,3 5,0-

79/v25

Table 2 (continued)

Meicapane - Deposit

_ _ _ _ _ _ _ _ _ _ _ _ _ o r r o ' E S u r f a c e o f B r o n z e ,Mane and Con- I ou. in ronse, 'KSUI±1ication 80 xcentration (%)WEm2 /3

vensylaezcaptan CJfSH(0.045) ()19 ,

ThUoiao oSs

0. 0C

(o~s~o) LJSH0

C C C0* CC~ 0 -C C

C C- CC

C ~ - ~ ~- ~ --6

isulfur and mercaptans with various chemical structures on antimony-bearing bronze.t

Further study of the sulfur compounds with various chemical structures pe.-it-

- ted the conclusion that, among the sulfur-containing compounds In fuels, the corro-

" sire compounds and inert compounds may also be accompanied by compounds with a pro-

* tective anticorrosive Influence on the metal.

- It was noted that bronze strips after a 6-hr test at 120 - 1500 C and certain

"-fuels of various composition and purpose (for wample, T-l1 Baku straight-run

kerosene, and cracked k.,rosenes of certain sulfur-bearing crudes) become coated with

a shiny film of steely or golden color. The film is weak and can be renoved

-mechanicallo Underneath the film, the "etal has an undamaged and well preserved

surface. The metal lose in this case Is nil or negligible.

It we obvious that we had to do with a protective film formed and renewed

--under elevated temperature conditions as a result of cheica• Interaction between

-certain compounds present in the fuel in ver7 -nel amounts and the metal.

Table 3 gives the results of a test with antimony-bearing bronze in several

fuels.

The branse protected by such a film does not bcom corroded and, consequently,

does not lose weight. No adhesive deposits are formed on the metal surface. More-

overj, the presence of the film on the metal excludes the catalytic Influence of

copper under elevated temperature conditione, in the presence of atmospheric Oaqenp

--on the unstable part of the fuel, and as a result, the amount of deep oxidation

-products formed as Insoluble sediments sharply decreases.

It we noted that In certain cracked kerosenes, in which the film we not

* foned an the metal after addition of small amounts of nitrogen-containing can-

Zpinmds, a shiny film of golden or steely color did appear on the natal, and the

of the bronze, together with the deposits, dropped to very low values.

"Such a effect we accoanlished at l°C for the cracked kerosene of the Noscow and

shew refineries.

ni

27 -•

The cause of the film formation on bronze (this phenomenon was observed on

'bronsee of various grades) was apparently the presence of compounds containtng suul-

.for and nitrogen.

A somewhat greater clarity was obtained an studying certain individual cam-

iounde.

Table 3

"Corrosive Activity of Certain FNels on Antimony-Bearing Bronze

I., i•-wUaon of Test 6 hrs

Pool and Its Corrosion IDeposit ReakCharacterization 1 pM 2 jon Metal fRmrC

Test Temperature 2200C23-1 writh 0.0• smrcaptans * e 7.1 1,0 Porous, corroded metal

"Cracked kerosene from Moscowrefinery with 0.94% sulfur. . . 5.8 0.9 Samse

, Cracked kerosene from Kybysh.evrefinery with 0.66% sulfur . 0 0.1 Shinyofilm of steely

, Cracked kerosene room Saratovrefinery with 0.5L1 sulfur... 0 0.2 Shim _fila of golden

"J T3S-1 vith 0.10% sulfur. .. . . 0. 0 Sameftrght-run kerosenne with0"0*2O 01-oul.ar . 0 . . . . 0 00 0.5 sa we

Test Temperature 1500C

:1,4 T3S-1 with 0.01.5% mercaptans . . 7.5 1.2 Porous, corroded metalCracked kerosene from Moscow surfacerefinery with 0.O9 sulfur. . . 6.4 1.0 3metrickery with 0.49 $U . 1.1 2.2 Same

Cracked kerosene from Saratovreflnery with 0.$1% sulfur... 0 0.2 Shaiy fila of golden color

14., T With 0.0 sulfr. . . . . 0.3 0.3 Same3t ght kerosene wt

v *0 0 0 9 h 0 093 0.5 so"e-Jd

4.4

we had avallable l-phenrl-5-iercaptotetrazole and Individual pyrasolnnes.,

* ,qutheelsed at Noscow State University at the laboratory of A.P.Terent'yev:

... 1-thidocarbmde-.35j5-triaetlWlpyrasoline* 1-phuoyl-3,5.5-trTaeth~lpyrasolJne* and

- ~** 3-m*.-l-pha lPyaO]tne.

NC:• ....... 1

-4 These compouds were added to fuel T3-1. which was highly corrosive because of

* the presence of a considerable amount of aercaptans (0.045%). The 1-phenyl-5-

--ercaptotetrazole was added to the fuel in an amount of M.O05O, and the rwaining

Table 4

Corrosive Activity of Fuel in Presence of Individual Hydrocarbons

•±Corrosion Deposit Precipitate

a of Bronze Ban Insoluble in

ddition Formala oBronse Fuels,

Without additives1-phenyl- 5-secao 7.11 1.6 1.t•trasole (0.005• " • -n- C- S11 0.3 0,3.

NN

1-thiocarbamide- Y0-3.p5. 5-triAmethtl- CI Is C --C ,0.5 0 ,31.

pyrazoline (0.01%) N

N

CMS1-phsnyl-3,5, 5-tri- NFHtmethylpyrazoline ClI. C--CH, .6 0.8 0.7(o~o•) I AI.D!

*(0.02%r ,

&-sinno-l-phenyl- Cellspyroasollne (0.01%) Cit -C--Nil, 7.f) 0.. 1.4

ICH, N

N

Sempoixmd in an amount of O.C]! each. The fuel was then tested for its tendency to

• -eerro antiamny-bearing bronze under standard conditions (6 hrs, 120 0C).

Table. , gives the results of the tests.

The fonation of a glossy film was observed on testing a fuel with l-pheanyl-5.-

- -mercaptotetrazolee and c-th:e b de-3j5•-tlmtWipyasolne. h a film was

-not observed in the other eases.I

JICL-579/yI9

f-om the data given in Table 4 one may, with a certain amount of caution, draw

a pellianear conclusion.'1

The sharp decrease in the amount of insoluble sediment in the fuel can be ex-

plained as due to a Ocoatine of the bronse surface by the film, as a result of

which the catalytic action of copper on the oxidation process of the fuel mercaptans

'mid other instable components was prevented.I"

S In this connectionp the amount of adhesive deposit on the metal sharply de-

areased. Better results in corrosion prevention and the formation of a protective1"

Sfil two shown by compounds which, in geneal, consisted of a heterocyclic ring*

ohamnctorised b7 the presence of several nitrogen atoms in the ring# and of sulfar.

The nitrogen atoms are directly linked to each otherp while the sulfur is attached

to the ring in the form of a thiol group or over a double bond. Such a heterocycle

m y adet in combination with the aromatic ring.

* Of course, these data are far from rufficient to allo the assertion that the

*tomtien of a protective film on bronse is due only to the presence of compounds oW

hi structure in the fusel. owe•or, in eonnection with the compleity of the

"pestiat, this assuptign was adopted as a preliminary 1Wpothesia, in view of the

feet that such compounds my, in principle, be present in fuels in mall mmuntse

iorisain 'larificationC may ýbe achieve&~ by attu~ing tie non-tdrocarban compo-,

-..itisa ef the oUels.0 0 6 o asp°sit portimi of the craec• & kerose•ne produced from Baku aid Eastoern

e1ass wa separated chromatographicanl on sLlca gel. These asphaltic substances

'-were characterised by high nitrogen, sujlf, and ex'sen. The portion of the

as. aphaltic substaneo o is treated with a 7% alcoholc4 alkli solution and vacwI- ,

- 4Lmti.U4 ?T1d . we wer dealiung with the tot asphalt and its neutral portoM

-- *"bh m ted to 93"95% of the total.

Snce the tota asphalt compounds had been treated with an alkaline solution t

"ebtaft the neutral compounds, we had a ig to consider that no compounds with a

GO-o

I

Jthil group could have rmlaned In the neutral portion. Tot, the neutral portion of

*the asphaltic Compounds was likewise characterized by a high sulfur and nitrogen

contento, Table 5 gives the elmentary composition of thee compounds.

Table 5

1'nentary Cmposition of Asphalz.ic Substances In Fuels, %

cked Kerosene, C f 3 Ni c)

"Baku refinery 8 O,34 9.41 0.9 2.73* Moscow refinery 77.41 9.5 3. 1 1,13 8.27

Saratoev refinery 75.13 9.33 5:111 1.09 9.35Alatow Winery e7.30 q.81 4.11 1.23 7.5S

To toot the hypothesis that the asphaltic substancee of the fuels contam

sulfur and nitrogn-bearng compounds of beterocyclic structure, In the presence of

which a protective film Is formed at elevated temperatures an bronse, we ran tests

Table 6

Iffect Ot Total Asphaltic Campounds from Cracked Korosenes an$4 the Fomsation of Glossy Film on Bronse at 2200C

-Total Asphalts Added to 8T04 sit Sufceo

It,.. No addition. *..eee.* - f .1 1.1 j Pous,Croaked kerosene from Baku reflnery 0.0 11.4 0.4 c corroded

*: Crkekod kerosene from Moscow a 0,01 1.8 0.0Cracked keoeene from Kuybyshev 0 0.01 1.0 0,2

jl - Cra•ked koremne frm Sasoy * 0.01 1.3 0.-8 3ofe fluIt; Creaked keraemeo from fttyshwv 0 0.01 0.8 0.2 J

A ,, t 150f

-f Ute moot orroolve fuel, TS-19 with added asphalt* from'cracked Ierosmes. The

-- toot emnditiosm wer the eami as those alread descibed: testing tia 6 his, tom.

powatreDO and 150%, blouse of variouspgades.e

~~1~3-

- The testing of fuel amed with 0.01 0.02% of neutral asphalts, separated

Imtr the cracked kerosenes produced by the Koseowp Kulbyshevp and Saratov refiner-

lee showed that although the metal loss and the deposit on the metal decreased to, about halts no glossy film was formed.

•. An entirely different picture was observed when certain total asphalt*, not

"treated with alkali, were added. In their presence, the formation of a shiny

, olden-colored fM an the surface of the bronse was observed (see Table 6).

Based on the data obtainsd, the following preliminary conclusions may be drau,

which will be refined as the work continues.

1. The nmon-)drocarbon part of certain fuels contains copowunds which, in very

• sm all ents, are able to interact with copper and copper alloys, forming a shiny

protective fn which prevents the corrosion of metal, and also its catalytic action

* an the unstable portion of the fuel In an oxdiuing medium at high temperatures.

2. There Is reason to believe that these compounds are of heterocyclic strue-

- tune, with wen nitrogen. atio or with several nitrogen atams lIInked to each other.

- The tol group or sulfur atam is attached to the carbon of the rift, Thebe-tsyvclie rifg my be conjugated with the bensene ring.

.. 3. The effectiveness of such compounds in the asphaltic portion of a ftel de-

.puends on their imunt, on the present* of various other compounds which are corro-

• sive or, ty virtue of their inertness, simply lower their concentration, and also'.4

depends an the tmerature conditions wider which the process takes place.

4 - &.1Ve hives obtained cmpowadse which, wen fojmig part of corrosive fusol, are

Able to form a Oprotectiv. film an the surface of copper or Its. alloys. This wil

. p,-preit the us* of larger assortent of crude for the pradmctIn of fuels than is:tho saso te"Y.

to 32. -Aay-$ t

qo -- . .. . ... . . . . . . . . .. . _

SDI UOGRPHY

!1. JohmsoupCoRoo ?lznk#D*F,o and NIXMOnA*Co - Xd*.MChm., Vo1.46, No.10

*(1954), p.2166

!2, - S*Aog*J@~UM1, Vol.62# No.2 (1954)t p.107

13.CbrtkovYu.D. Zrnlov#V.NL, Narinchw~ko,N.I.t wAn ShchaglnoV.N. -hmi d

'TopI~va, No.22 (1956). p.47

A.o C~herkow&Ya.B., Zr*3ov,V*N., Narilnchenk@,N.I.t =An Sbsvgln,,VN. - Xhlaoi Tekho

1Tvqlal I Nuols NO.7 (1957). F.57

5. Raa,.G.&Wn Do IangtB.W. - Proo.Aa.Netrolem znst.IU, VOL.33 (1954.), P.236

.6. Cataldi,KA,o Askevold,R*Y.9 and HhznaborgertA.e. - Petrolom Refiner#

UoLU32 No.7 (1953)o P.345

7.Vlnogradov&GoVo et al - Vestnik AN SM.t No.9 (1955). p.35

-. Krmn#So& and TammnrmnO.So - Neft.ihos., No.2. (155). p-71

.. Chbu'tkovyaj, and zrolovtv*No - vest.vosd.Flotao VOL.8 (1957)o P.63

ý20. 7mA@3uldy,YuS.. Krern,3*E., SMmqemng.rL.j, mid Shor.G.I. - KhtmA. Tdch.

?qolau 3.4 (1956). P.37

i

Itp

TUB EFFET OF ORGANIC SULFUR COPOUOMDS ON THE UW-TEPERARE ,

S1 N l AND OXIDIZaBIniT OF KMSEEEGASOIL FRACTIONS t

", Z.LA.biblnshteyn, DoVoLosikov, YeeP.Sobolev, LG.Zeychlk

*D (Reseazrh Institute for Fuels and tabricants)

The iacreasing use of sulfur-bearing fuels and the ealrience acuimiated as to.

-their peculiarities# have raised many questions that need profound study, .

The specific nature of Diesel fuels produced .frce Ural-Volga crudes is eU- D

plaa•ed by their chemical composition, which Is characteri•sed by a high content of #A

p. aff Iic end arwatic hyrcarbons and a relativeh7 content of eulfur aco",

psudeo which reaches 5.- 7%.

-- The sttdy of the effect of the concentration and structure of sulfur epond

-'n the ImJ-teiperature properties end oxidizability of the fuels containing such 1

-2eeuipmdo occupies an mportant position In solving the problem of a ratioml

"Lutlisation of slfur-earing fuels.

o-- Tme Imstemporzatue properties 'of Dosel fuels are of Interest to practical 33

-waters prmrily with ard to their pumping qwality. Fiipift quality is a very' !

-u- imperkAt paromterg, since the suppl* of a precisely preodeteoined mont of fuel to

Sthe eowestios cember of a Diesel angim Is one of the fudamental conditios for .

-#Its stble, W And uaitempted operation. The problem of ipmpig quality for most

3e. L,

-- Diesel fuels arises only in the region of temperatures below O°C. Being a function

of chmical comaposition, the pumping quality of dr7 fuels, frm the physicochmirncalI.

point of view, may be characterised by their viscosity, pour point and cloud point.

In evaluating the concept of pumping quality, one must distinguish pipe pumping

quality and pimping quality through the filters of the engine fuel systma. Pipe

.pimping quality In a function of the fluidity of a fuel at low teperatures and may

Table 1

Low-TImperature Properties of Eastern Diesel Fuel.

Fuel

Parameter a) TU 1ZTV YTU mental G3o$-42 569-55 488s--53 with 794

I. I I. Boiling range, OC :,e. :t:O -.". :vo, i:aot I', :CA:# :i 10 :1,0,

S Cloud pointC.. :, , is

Lw wax cont ent (s;l2d"hydrocarbons) by

; Zalosetskiy-Galand, I% of fuel i. *.. I.,- Absent. e,..% I.,a Absent

Aromatic h d oG-carb , e9...a; . . ,.=. :u.,4 M:e

%iAftir, S..... %." 1., tsi , 40.1 1. M. I4111i

a) Krauwkamsk fuel mixed with other fuels fro Eastern crudes

be ebaracterised by Its viscosity and pour point. The cloud point, fixed as the

nsteant of Crystallisation and precipitation of solid hydrocarbons from a fuel, is

I uIS itable'for estimating pumping quality through pipes. To estimate the pumping

"*quali tluough miltere, the cloud point Is very Important characterzing, as it

Sdoles the state of the fuel at which the* throughput of the filter elments may de-

e*rease. Diesel fuels with high naphthenic or awonatic hydrocarbons and low methane

hydocrbosIncluding hydrocarbons which are solid at low temperatures, are rather

35.~

Co. a • . .: : o 0,o . . .• • E # , . • • 4o . , ,. . .. k:, • ) ' • L . . 0 •

-wel pmped through pipes and through the filter elements of an engine. They are -.

UasSilY Characterized by low pour and cloud points. For low-sulfur fuels, the basic

eliterion which determines the pinping quality Is the content of solid hydrocarbons,

which Is reflected in the pour point and the cloud point. The situation for sulfur-•4

" -bmina-g fuels is different. The low-temperature properties of sulfur-bearing

Dliesel fuels, with 5 - 8% of polar molecules of sulfur ccapoundsp depends not only

-oa the content of solid hydrocarbons but also on the content of sulfur compounds,It

and apparently also on their structure.

Table 1 gives the low-tenperature properties of Diesel fuels and their content

of sulfur and aromatic hydrocarbons.

It le obvious that the cloud and pour points of the samples studied depend not

ons• an the content of solid hydrocarbons but also on that of sulfur compounds. For

-esmple, the experimental Diesel fuel with NKZ, containing 1.680 solid hydrocarbons

-and 125% sulfur, solidifies at -19*C, whereas the Diesel fuel per VTU 486-53, con-

S taalng O.84% wax (after Zalosetskly) and almost the same amount of aromatic hydro-

Carbons as the experimental fuel, but also containing 0.76% of bound sulfur, solidi-

" -floe at -136C. A certain influence of aromatic hydrocarbons, owing to the presence

of a field of force which apparently Influences the surrounding substance, is also

.nt eumlnded. This may be noted In comparing the propoeries of Krasnokamk fuel

-. -,with feoel perTU 30542. These fuels, which have almost the same pour and cloud

point&, Contain a•most equal amounts of sulfur ounds but differ considerably ino42

• on it of @ A and arcmtie hydrocarbons. Apparently, the polar sulfur compounds

ont uiondensed aromatic hydrocarbons, like the asphaltic substances, favor the ap-p - o of gof soli h c s preventing the formation of a

_4etaln t In the In the suspended stato. Fro t poit of view,

i-it om be postulated that a fuel with the same mount of solid hydrocarbons should

- have a bOtter pmpability through pipes at h4her Contents of sufur compounds and54-.

arintie tqdrocab. Mviously# the effect of sulfur compounds Is greater than

* I 36

-- that of the aromatic hydrocarbons*

Howeer pipe pumping quality is of secondary importance in Diesel operation.

.It is far more Irportant for operating purposes to have a fuel with good pumping

4 ~-

Fi. icag n rssr essTmeauei

Pa)pigDee ul nalbrtr upn tn

a)~ Dshrg n Pressure Versusler. o;b Temperature, in

a) Discharge, ltre~in

quality t~hrough the filter elamentes Diesel fuels produced from Eastern crudes,

eantatainlg an appreciable amount of solid tqdrocarbons and of sulfur omupounds and

armsiatic molecules that favor their aggregation, possess a poorer lov-tamperature

plamping qia&Uty for filter elammntse The experimmntal evaluation of the pumping

Squality of milfar-bearing Diesel fluels~mase on a labolratory stand with a filter

taken from a ZD-6 angine, with felt filter elements, has shown that the pimping of

the melua samples' falls sharply at plumping tmperatures corre*spending to the

elmd point qf the test samples. On this standi we estimated the pressure rise In

*fiat of the filter and the filtering power of the filter when constant pressue Was

mnalatained In front of It* ?be experinanst showed a sharp Increase in presuel be-

-:foro tOe filters and a decreasee In filtering power, noted several mintes after the

*texperstu4 of the ftel had dropped to the cloud point. Figures 1 and 2 shom the

F! LMy3

-i results of the experiments.

In the light of the above it is not without interest to recall certain other f

features of sulfur-bearing Diesel fuels that have recently been discovered. In s8me

cases, after prolonged storage of sulfur-bearing Diesel fuels in tanks and reser-

voirs, at temperatures above OOC, a layer of solid porous wax was found floating on

the surface. No similar phenomenon was* ..

encountered in the storage even of culfur-

"- "" '-free summer fuels with a considerable

""4,4• : 7 t amount of solid hydrocarbons,

"" •In B.V.losikov's opinion, this phe-

nomenon is due to the formation of con-

4Jf . - .- glomerates of solid hydrocarbons on drain-

ing the cold fuel; such conglomerates are

b) not Interconnected, owing to the influence* 'p

Fic.2 - Curves of the Temperature of the sulfur compounds, and are thusS'Dependence of the Discharge and

Pressure in Pmping Fuels on a attracted to the surface by the air en-3? z Pipio tralzied on addition or rpmmova of foe.1

2- ie fuel pe"r.. ... 4749-49;- 2 Dies-l fuel per VMU 488-•3; The conglomerates of solid hydrocarbons

:A .IL34 - Diesel fuel from Novo'Kmtyshev xefInery;S L25%; ' floating on.te surface freeze at, a 1loDischarge., rtif

Pressure before temperature, separating the fuel, and formo-. filter& kg/ca 2

a solid porous cake floating on the our-o . : ' o • o s ) P r e s s i r e b e f o re f L t r r ;..b) TPr peraturse °C; b) srkm- face. °A preliminary experimental check -

ii chrgeltr 11Aperformed by a brief blowthrough of the

expeime talfel with NKZ, containing l.65C of wax (after U16sostsiy and l.25% of4',

.sular, which had been cooled to -12eC. followed by further cooling for 6 - 7 hrs

to -20 and -30•0C showed that foams which did not disintegrate at a temperatureof #15eCv collected an the surface of the fuel. The porous mass reoved was melted

And maMned for wax (after Zalosetskiy, Dibl.l) and pour point. We found that the

VCV.579/1W3• •;; t ... . 4

.4- 5 o

0-Jwax; after Zalozetskiy In the melted foam was 4 - 6 times as high as its content In

Uthe folp and that the pour point ranged from 20 to 220C (the pour point of the fuel

-was-1 0 )

CMLIcal. Stability

The chemical stability of fuels characterizes their power to maintain their

composi tion without change during prolonged storage In contact with air under vari-

4-

ous climatic conditions* The resistance of petrolem products to the action of

0•

atmospheric oxygen, as sho by many :investigatores (tibl2 - 5), depends a n their

molecuala weight and chatcal cmposition.I'

No reliable data are today available on the behavior of Diesel fuels of varying

Schemical compoition during prolonged storage, in various holders and packages.4

To elucidate the effect of the concentration of organic sufur compounds, we

ran expertments on. the artificial aging of sulfur-bearing Diesel fuels in the

pres•nce of iron and copper* The kinetics of the oxidative processes during their41

initial stage was investigated.2.

- - Three samples of Romashkin gasoil and two specimens of Taymazy gasoil were4

-exidizsed To elucidate the influence of organic sulfur, it was necessary to have

-- fuels with the same hdrocarbon cmposition and different content of sulfur cca-

'pounds. For this purpose, the original. mashkin Casoil, containing 0.62% sulfur

-(ample 5o.1)0 ws twice deuulfarised. After the first superficial desulfUrising

• ilo f 14ca gel, the gasoil contained 0.32% sulfur whereas after Its oxidation by4

t;--.I2 at 60AC. fol.lwed by chromatographic separation of the oxidation products, It

-- semtainei s sulfur (sample No.o3). The Tmasy specimens were straight-run distil-H.

-lates, original and after 1ydrofining. The original distillate contained 0.96%0.

-rtlfur, and the tqdroflned distillate 0.*. Table 2 gives the characteristics of

-the gasolls studied.

"The sample of IRmashkin asoil were oxidized in a flow plant at 100C and an

~~1

*4.eI

.,ox•g'en flow rate. of 6 ltr/hr for 10 hrs. In all cases, two parallel oxidation R

experiments were run under the same conditions. Samples (2 - 3 vm) were taken .

uwring the experinent. from the product being oxidized, and their acid numbers,

* Table 2

1,, Characteristics of Gasoils StudiedIo

Roashkin Gasoil Gasoil

fPtsical and Cheilcal 76pecjje No. Specimen No.

Properties and Chamical 1 1 2 3L

""Density, 0• .. O,.,M1 11.14.,04 O'i ,,101; 11.&M . . .. hx- 'I

.. .R o ef tc v6 " In d e x , l~ . l , lj.lv j 1 . I I . • i 1 .slu l

"Actua gtieg, mOO Al... .,::4 Total sulfur, % ....... ,,.ei: e,.: ,,,,

914110ftary sulfur, % 11.11 1aIs AlowniS Hyduvogn sulfide, %Mercaptane % .oo....*.... ,,,,,0 01.002 Mg," no" 107en

- 8/Disu3does, % I " fl'tI *

.Residual sulfur, % 41. L 0,m"1 Acidityl, g KOHI/iCO al.. o .. I to,!$

Armtic 1 31- •"" ""Iodine ;usIitc - - -

9 t

i pw de numbers, ho dro31 nubers, and saponification ombers wore potentimetri-

A fter 10 tke of oxidation, the actual gum was determined in all sa•ple.. The

amples of Tqmay gasoil were oxidized in a glAss bulb at 1OOeC at an air-flow

° • rate of 10 ltr/hr for 1 3, 6, 99 'and 12 hrao. The optical density, which ws cat-

sdored as a function of t, accau.ation of asphaltic, sustances,, was maeaued in

nthe otiued specimgene by a photoelectric colorimter, and the acidity w"s e•asured04

* .psttioetically. Figures 3 7 give all the experimental results.

52- .Cms. f the Differmee in the Kinetics of Peroxide AemlAtion

54 -. .. •S* Oa eseldering the curve of peroido accvmlation for the three samples of

o o I •• .. . .... . . .

o . C. .. . . ..110- -- -

Roashkin gasoil (Fig.3)9 the substant.al difference in their character will be

easily noted.*

The accaunlation of peroxides during the oxidation of specimen No.1, at least

3I - Deufa-- sml

f I

I. a)C'4 1

a) Pe d b H s

l . b)

upFti .3 - Variation in Peroxide NIabers w ith TiseI ' (See Footnote on p.31)

)- I s1anlas- Samp~e dt~hO0.6Z.Z of su~lfur; 2 -0.32% sulfeur;- 3 - DesuiJrised sample

as) Peroxide inuber; b) Hours

g• up to the inads•m which" occurred after 8 brs of oxidation, is linear, which ii 'iot

c- ahbracteristic property of autocatalytic processes.

Daring the oxidation of sample No.2, an Inflection in the curve occurred after

-4 hr. of oxidation, and the character was clearly autocatalytic, whereas the in-

-efease In the amount of peroxides after 4 hr. of oxidation was very rapid.

"C The ac5• alation of peroxides in sample No.3 takes place along a curve Indica-

Sting the astocatalytic course of the process, but less Intensely than during the

e oxldatIon of .ample No.2 Daring alaost 8 hrs of oxidation, the absolute quantity

Sof perlxide on any stage of the oxidation of this sample was less than during the

C mes U In FIgs.3 - 6 were obtained by shifting the points of the ezpersental1--ow"e 1 by the Initial values (respectively) of the peroxdeo acid, and h4droylI e-lnbers, and the saponification numbers deterLined in ample No.1 before oxidation.

a..'I

-- xidation of the other gasoil (samples Hos.1 and 2). To judge from the slope of the

carvo, the mean rate of acculation of peroxides was higher in sample No.3 than in

s•e No.1.

If organic sulfur his antioxidant properties, thw. the increase in the rate of

peroxde acc@mulation with decreasing sulfur content was entirely regular. But the

cause of the difference in the character of the kinetic curves of peroxide accmutla-

tin rmains wmexplained. For exmple, on oxidation of sample No.2 the maxima

ammomt of peroxides is formed, but the Inflection of the curve takes place, not

t after a hr as In sample No.l, but twice as fast. In the case of the desu2turized

keorosene (sample No.3) the peroxide accumulation curve has no inflection and is

considerably flatter than the curve of sample No.2. The peroxide accumulation mi.-ve

In sa smple Nol is not of autocatalytic character, and the absolute amont of perax-:'4

id1es deing almost 7 hrs of its oxidation Is higher than that of sample No.3. To

.eplain the difference in the kinetics of peroxide accumalation on oxidation of

those ostples of gasoil, the following considerations may be proposed: At low con-

eentrutions of organic sulfur (sample No.2) peroxide compounds are formed not onl

by odidation of the hyd-ocarbons, but also by oxidation of the sulfur compounds.:14

Sbseqpet~y, at a certain stage, on decomposition of the primary oaWgn compound

of. .. i oo e salfUr suabtances are formed that readily react with the peroxides and,,

-- 4- this way dscrease their concentratlon. If the sulfur concentration is high, then

A° f rmation'of swbetanc:4 readily reacting with the peroxide. proceeds rapidl,

aW their esapt tioi sufficient; camnseentC• the ?qdrocarbo peroxides'4 ,

tmied wapli react itthen and have u time to accumalate in the substrate. In

.. . e :' totalpetroxide concertration is the resltant of two processes. The

•e ltem In samples U.]. and 2. Tbe curve of the pwrxide 'bwers for sample

o.3 h aa mawdm, which Is entirely asdssible under the mild cnditions of a

-.Ief aidatiom, evn In the absence of antioxidants. The mooth rise in the qian-

Go_6. -.- --

IS•5"/v n• i1

-2tity of p.-wdides for the desul!furized gasoils :indicates the relatively low conver-'

si~on of the peroxides, If :it takes place without interference of extraneous factors.

The fact that. the rate of accumnulation of peroxides In the latter case Is high~er

than during the oxidation of sample Noel# and that In a number of oxidation stages

their absolute value Is lower than in sample Noel$ is explained by the fact that In

'samples Nosol, and 2 the sources of peroxide formation ame the hydrocarb.. -1 and

maluftar compounds, while In sample No.3 the only such sources are hydrocarbons.

Pr jinetics of ForMtion at Acid Substances

As will be seen from 7ig4., the accumlation of acid substances In all cases is

linear. The original samples Nos.2

4 -"- and 3 had-no acidity before oxidation.

The acidity of sample No*1 before

* 40 -t oxidation was 0.2 mg. For convenience

4OW of comparison of the kinetics of adids-4* tion of these samples of gasoil, the

d ~second cuave ()A) has been constructed,

- e Fi.- Kineticsof VariationIn the with the original valueof the acidS'- Content of Acid Substances In Sam-

pies, of Casoil from Ramashkin Crude number subtracted from all valuaes of(3ee Footnote, on p.31):

the acid numbers found. The slopes ofI and I&- pciaen with0*62% of

wmlfta'; 2 - 0*32g 3; 3 -Desul- the kinetic curves are different, The* hrimed samle

smallest slope Is formed by the curve

e -f sampl 2p the intermediate position Is occupied by the curve of desuifturized,

K~aaeil.while the highest rate of formation of acid compounds Is for the original

gase"i Apperentlyp the cause for the Increase In acidity found on oxdation of

-spesiam No.1 ane not mnly the organic acids formed as a resut of the oxidation of

tqdsea'bmsbut also the sacid substances formed on oxidation of elmentary sulfur

-and of eugani. sulfuir compounds., The role of elmentary sulfure is distinctly mod-

PM l A

V tested If we compa.re 'the kinetic cwve of the original and desulfiarized &inashkin

SdT~suiav gasoila. The ?uyazray sulftr-bearing gasoil (Fig.4a) (sample N.4I) which

afe qdolicj3- .4

4"64

!f' 4W not contain elementary sulfuarj had a lower acidity at all stages of oxidation

! J v

30.. 4l .. .

V.-

,~~ l'il/, - Ve~le a cd• ro ao•[ k~~ C--i CeC

444ftg*S Kinetics of Fonution of Hydroql-Contalinig Substances

(3* 7g0tno-m~ P.31):""o a nd a.8empU with,•- 31o2 -0.32%. 31

"54 d. n e a a-iity UM of stpl a5._

32 .0C C.. ..CO

Gog

• ' -. . , -. C• •C

C .. C- CO

°_________ °___________________________ -___________4____________________-________ ---. - C-________- ________

"Kinetics of Formation of Rrdrovl--Containin. 3ubstancas

* :

In considering the kinetics of accumlation of hydroxl-containing substances

(Fig.5), our attention is struck by the radical difference in the kinetic curve ofI,.

Ssample Nf.]. The accmulation of hydroql-forming substances here is linear, which

'Indicates a retarding process, but the rate of their formation is considerably

* higher than that In sample No.2,II

The center cove (sample No.3) has a distinctly aut.cata~ltic character. The

* rate of foration of tldro7WI-containing substances on oxidation of desulfaorsed

gas oil in the last analysis becces the highest of allo

The causes of this phnonmena are evidently as follows: During oxidation of the

desulftarited gasoil, the process proceeds autocatalrtically, and the accumuation

of thqhsr l-cmtaining substances depends only on the process conditions and the

. Ihydrocarbon cmposition of the test gasol.o The addition of a smal quantity of

. suI3fr-cotaining compounds modifies the character of the conversion of peroxides.

The reation of condensation begins to predminate over the resction of deccmposition,

* and as a result the absolute quantity and rate of accumlstim etof bdroq7l-containzng:4

-substances decreases.

-047 At 4 le qnttes of sulfur mpouds especially of the suld type

•an eidatIve decmposition of peroxides (Dibl.lO)j with fornation of ?Wdroql-

sontaInIng orgnic molocules, Is apparently possible. This is obviously the cause

-•a thn pecullar character of accumlation of these substances &ring the oxidatign$4

of - o oil (smple Wo.1). 'It nsot be noted that also this curve should be shifted if

hie. direction of the absissa axs, since a ma quantity of droql-containing

s -bdtaneee, Uwdch we at first neglectedI, im present In the original sample, even

r -,before the begIuti of oxi~dation in the reactor.bnM1

Nhpeedfloab6 substances ar formed to onsidable extent as a result of the

• si

jInteraction of acid and hydroxyl-containing substances* It is interesting to note

that the character of the curve for sample' No.1 (Fig.6) is to some extent connected

it

* - -- -

in. 41~~

If' a., - - -

-- eT

4'

" i)Flg.6 - Kinetics of Variation of Saponifiable 3ub stances(So* Footnote an p.31):

32Iland. la - pecinasnwithO0.62'. ; 2- 0.32zS;

14 3 - Desulfurized sample

M. &) saponification value; b) Hours

-with the character of the curve of the hydroqi1 numbers for the sine &&*oil.. The

41.1

exerts an Influence an the form of the curves of accu=lation of the spnfal

'. -ostuucefte Apparently here, too, the, role of the acid campouns formied duzing od.46,

- .dation of variou comspoiunds, Is not excbaded. It Is preciseU. for this roeason, that

the total quantitr, of ýsaponifiable substances Is ma:uim for, all,,oxdation stages o

saqdle 30.1. The retardation of the reaction of decomposition of the peroxidde ccmi

_>powda ft* to the sulftr compounds daring oiddation of sample No.2,p which led to a

-2M 004ts'enamt of acid and tydroqi Gcomponds than in samples Noe.l and 3a sh-uld

5dI

uczO.57,ft

4naturani lead to lower velocities in the formation of saponifiable substances dur-

inM the oxidation of gasoil No.2 than during the oxidation of samples Nos.1 and 3•.

The kinetics of accumulation of saponifiable substances during the oxidation of

the desulfurised gasoil No.*3 depends only on its hydrocarbon content and Is directly

related to the character of the accumulation of acid and hydroxl-containing sub-

stances during oxidation.

The kinetics of gum formation during the oxidation of Romashkin gasoil was not

*Investigated, owing to the lack of a simple and reliable micro-method of determining

"* Table 3

4 Actual Cum in Original and Oxidized Samples of Rmashkin Casoil

Actual Osn- pectmen agiC l

* 10. Before After•. Oxidation Oxidation

2 i.(S - 0.62%) 34 154 .

4 2 (3-0-32%) none 2433 (desulfur- none 84

184d)

-the condensation products; nevertheless, after oxidation of the substrate, we did

inavetigate the actual gum, (cf. Table 3). It %as found here that the maximum mount

-of Sa wes formed in gasolls containing sulftr coounds. This latter circumstance

-'ms onmifeeted with particular distinctness In considering the kinetic curves of

~-vsrlatim n L the optical density of sulf~uu-bearing and desulftizied, TVa~uay gasoile

Ve* relatively .14 oxidation conditions, the gum formation in gasoll contain-.4

I-Niu O.O% sulfur ws vew rapidly retarded and practically failed to proceed at all

-. *nut 9 hr. of emidation. On the other hand, the sulfur-containig pasoll propes-

1 RL579A 4

sively accumulAtes g substances. Taking due cognisance of the presence of a 1

ertain mount of gum In the original Romashkin gasoil, we may consider that the I

relatively mall amount of sulfur can-

t pounds (0-32%) effectively favors the

"1- • ,. process of conversion of the peroxides, ,

a d,.which is directed toward condensation

and,, consequently,, also toward gum formna- .

tion. .1

. b) Starting out from this, it is pos-1lo

Fig.7 - Kinetics of Variation of Opti- sible to postulate that there should .1"mal Density of Gas Oils from Tuymasy

Crude before and after Hydrofining exist a *threshold* of sulfur coneentra-"an their Oxidation

tion., which, when exceeded, no longer--4 F- el before hydrofining; 5 - Fuel

after hydrofining leads to effective gum formation. On the

a) Optical density; b) Hours other hand, apparently, for the develop-

, ment of processes of gum formation, a

Shigh concentration of sulfr componds is not necessary, and aUl that is necessary

* is that their content sItal be sufficient to interact with most of the peroxide cam-:14

. pounds formed during oxidation of the hydrocarbons.

Hence It Is clear that the value of the 'threshold' of gum formation for the .4

concentration of sulflurompounds is dependent om the htrcarbon cenposition of the

gseoil under study and udoubtedly also an the structure of the sulfur cmpounds. .4 L'

.j'k The Effect of Gums Contained in the 0riginal Gagofi .

* 41#in ooftsetion with the litsratire considerations an the anttioxdant action of .4

gs.-like substancesia It. Is epedien to ealuaste theirý inflence on thei kinetj~s eM d

,,eha- eter of the dfdative process.

FM a anparison of the kinetic obtained by oxidation of sample Noe.l 41

-asd 2, and the amounts of actual um determned in the oxidized samles, it will be

: ucz9/V ,1h8 ._" ....

o * . 4

¶!

clear that the maximum amount of products of oxidative decomposition appear in the

"" g•in-containing sample No.l& and the actual gm found in the degumned and oxidisea

ample No.2 even exceeds that of the newly formed gum in the oxidized Simple NoeL

At the same time, a comparison of the results during the oxidation of the do-

gummed samples Nos.2 and 3 (sulfur-containing and sulfur-free, respectively) con-

Ivincingij shows the Influence of sulfur-bearing substances, but not of gums, on the

kinetics of decomposition of peroxides and the process of accsumation of condensa-1'. tion products.

These data prove that the gum-like substances in the original gasoil have no

,substantial inf2uence on the character and kinetics of oxidation of that gasoil.

L It has been established that sulfur compounds prevent the autocatalytic

*develqment of the oxidative process.

20 The "antioxidative" functions of sulfur-containing compounds consist In

their Interaction with, and in the products of their oxidation by. peroxide radicals32

-or bsdroperoxides of totrocarbons.

3. &y preventing the decomposition of peroxades by the free radicals, and# con-3 o. i_sequentlys the development of oxidative chains, the su.fur camp•nds accelerate the

-'processes of oxidative po2uyaeisaticn and condensation, as a result of which gum-

-Ike substances acculateo A high concentration of sulfr cwpounds is not re-

quired for an Intense accumulation of such gum-like substances. The mainma amount

.et sulfuAr' in gasoll that is permissible from this point of view depends on the

_.ehanical structure and relative quantities of the sulfur compounds containing It and

Isma the chemical composition of the gasoil being oxidized.

i 4 .. Liftr compounds at low concentration prevent the formation of acid,, 1Wdrozyl-

o ta g and sponiflable substances which are due to the oxidative decomposition

_,of peroxiddaso The optimam concentration of Ototal sulfwa that wil prevent an ac-

-" - -. -.... .... . .. .... . ....---- -.4- .

-camlation of these substances derend3 an the chemical structure and relative amounts

lor the sulfur compounds composing it andi, ýapparetntlyi, on the chemical composition of

Athe guoail being oidised.

" 5. The gtm-liko substances contained in the original RCMashkin gasoil are not

Antioxdants, and have no substantial effect on the character or kinetics of its

olda"tIon.

6. The results obtained indicate the need for deep extraction of the sulfur

c.anpunds from the kerosne-gasoil fractions. To obtain optimm results, not only

en gun formation but also on acidity, however, it is apparently necessary to leave

Sa U amount Lof sulfur compounds in the gasoils. The optimum quantity of "favor-

able and preventive sulfulr should first be established for a petroleum product to

be q•Wr.fined.

7. The presence of sulfur compounds in waxy petroleum products favors a de- s

rease in the temperature of structure formation.

L!

DIBLTQIAPH

. 4 ." ibak3.BN. - Analysii of Petroleum and Petroleum Products, Part Lo Asnefteisdat,

klcu and leningraid (194.8), p.367

:3i._2 Chenoshukov,.I.Z and KroynS.E. - Oxilduability of Kineral Onis.

4" ~ Ogetoptekbiadat (1955)

.3, Ivnov,!.., - Intermediate Products and Intermediate Reactions of the Autoxidb-

44 tim of lydrocarbons. Gostoptekhisdat (1%9)

46 4- Sergisko,.R. and GalchP.U..- Zhur.PromlKhla., Vol.28, No.7 (1955),

4. w*735-7&3

jo 5. 3eru'ginkoiS.l, GCaUchPe.,. and IyerlsvV.I. - Zhur.Pr•.iKLm., Vol.29 (1956)o

, • 52 wP.r17 -l?26

54.6 Slerglyeno,,S.L, 0 a2.ichP.*Ne, at al. - Zlwir.AnaL.Kha., No.6 (1956),, pp.731-734-- 4

.7e 7. Sgyemko,S.R., R .alich,P.N., and tlvak,L.L. - Zhur.Au'l.AKlh., Vol.12, No.1

58.11c_ p5.... _ -

""UC01- - -0 -..

(2957)v pp.1.39-21.2

"8.U BolD. - U.S.BUreau of Mines. RtepIest*ig., DOe. (1941)

'9. Rirch.S.F. and McAllanD.T. - J.Inst.Pstrolem, Vol.8* No.333 (1951)v p.d1

t0. vwaovOK.I., and Savinova*V.K. - Questions of Chemical Kinetics. AN SSSR Ho.,cOV

ti- (1i5)9 p.250

.AneMrs to Questions

to t Which Is it that affects the for.ation of a wax layer on the surface of

1" , a fuel* the presmce of sulfur compaundl, or the chmcsa composition of the hydro-

2, .carbon part of the fuel?

".% An"ter.O We can give only a preliainazr answer, since this question needs furtherStv**. We did find that armatic !Vdrocarbns exrt an Influences although to a

.; Jleser degree than sulfur compounds.

32.

34.-

4-1.'4 2--

44.

"4$-0I

562

58..,, !. . .